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Bench grinder

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Brian Rutherford25/08/2018 10:46:18
80 forum posts
3 photos

Been wanting a new grinder for some time as mine was given to me minus the guards and vibrates quite a bit. Noticed screwfix had dropped the price of their Titan 8" to £35 so picked one up this morning. Surprised they had any left at that price

John Baron25/08/2018 12:01:30
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90 forum posts
16 photos

Hi Brian,

The usual issue with vibration is out of balance wheels, have you tried truing the stones with a dresser. I have a diamond one that I bought. After using it the vibration almost completely disappeared.

Just re-read your post.  You really need to make some guards for the old one.

 

Edited By John Baron on 25/08/2018 12:03:17

Brian G25/08/2018 13:20:15
589 forum posts
25 photos
Posted by John Baron on 25/08/2018 12:01:30:

Hi Brian,

The usual issue with vibration is out of balance wheels, have you tried truing the stones with a dresser. I have a diamond one that I bought. After using it the vibration almost completely disappeared.

Just re-read your post. You really need to make some guards for the old one.

Edited By John Baron on 25/08/2018 12:03:17

With a new grinder available it seems the ideal time to fit pigtails to the old one and turn it into a polisher.

Another Brian

Swarf, Mostly!25/08/2018 13:29:08
497 forum posts
41 photos

I suggest that it's important to take the power rating into account when assessing the value of a bench grinder. One with a 350 Watt motor for £35 could be a bargain - one with a 170 watt motor for £35 is likely to be a frustrating nuisance! Especially with 8" wheels.

Best regards,

Swarf, Mostly!

Brian Rutherford25/08/2018 20:45:09
80 forum posts
3 photos

Yes 400 watt motor. Seen a few posts on here previously recommending them.

I shan't be using it till next week but will post an opinion on it. Putting a green wheel on the old one and will use the coarse wheel for roughing tools out

AJW25/08/2018 21:47:40
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275 forum posts
117 photos
I can vouch for the diamond wheel dresser, they work well but what a mess!
I have my grinder mounted on a wall bracket with wing nuts, I take it off and dress the wheels outside to avoid all the abrasive dust.

Alan
Neil Lickfold25/08/2018 22:08:38
568 forum posts
102 photos

I have found that the hole size of the wheel and that of the shaft, is too loose. I suggest either turning a better inner bush, for the wheel, or using some form of tape, to make up the diameter to a better fit. Once the wheel is in position and clamped it will be good. Cheap wheels need the sides dressing as well as the diameter.

mechman4826/08/2018 11:24:52
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2461 forum posts
371 photos
Posted by Neil Lickfold on 25/08/2018 22:08:38:

I have found that the hole size of the wheel and that of the shaft, is too loose. I suggest either turning a better inner bush, for the wheel, or using some form of tape, to make up the diameter to a better fit. Once the wheel is in position and clamped it will be good. Cheap wheels need the sides dressing as well as the diameter.

Back in the old days abrasive wheel manufacturers supplied spare bushes to compensate for different shaft diameters or the inner bushes were made from lead & could be made to suit shaft, not so these days. I strongly suggest that you DO NOT use tape around the motor shaft, you will only introduce imbalance & concentricity issues with the wheel, far better to make up new inner bushes to suit.

George.

Simon Williams 326/08/2018 11:28:30
412 forum posts
67 photos

Posted by Neil Lickfold on 25/08/2018 22:08:38:

Cheap wheels need the sides dressing as well as the diameter.

 

Sorry to take issue with this, but the Abrasive Wheels Course says never dress the sides, for the same reasons that you shouldn't grind on the sides and thin (weaken) the wheel. It also puts forces on the wheel matrix it's not designed to withstand. If a wheel won't run true (as opposed to running eccentric) bin it. Either the centre hole is skewed or the moulded faces are out, either way it's only use is a doorstop.

Of course cup wheels are designed to cut on the edge axis........

Edited for note about cup wheels

Edited By Simon Williams 3 on 26/08/2018 11:30:05

Ady126/08/2018 11:34:05
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3463 forum posts
513 photos

A lot of my stuff is now only teeny tidy up work and I find the angle grinder with its thin wheel more useful

Even for bigger work like chopping a piece of HSS I find it easier to use

2cents

Speedy Builder526/08/2018 12:16:11
1820 forum posts
128 photos

My Blackspur packed up the other day after 25 years of abuse. Tried a different socket before dismantling. Found out the switch had disintegrated, found a spare DP switch in the come in handy electrics box. All up and running .

BobH

Joseph Noci 126/08/2018 12:32:11
542 forum posts
832 photos

Simon Said..

Sorry to take issue with this, but the Abrasive Wheels Course says never dress the sides, for the same reasons that you shouldn't grind on the sides and thin (weaken) the wheel.

I am not sure this is strictly true anymore with today's wheel technology and makeup- No wheel will really run true side-to-side, and a light side dress will do no harm.

It also puts forces on the wheel matrix it's not designed to withstand.

If you are applying force sufficient to cause the wheel to fracture, you are WAY overdoing it! Use a diamond dresser, with a light touch and all is safe. Do NOT use those spinning teeth type wheel dressers on the sides..Anyway, there is normally insufficient space on the sides to get such wheel dresser in.

If a wheel won't run true (as opposed to running eccentric) bin it. Either the centre hole is skewed or the moulded faces are out, either way it's only use is a doorstop.

Sideways wobble is more often than not due to the stamped side clamps being out of true. Those side clamps have no machined register and the part sitting on the motor shaft is punched not machined, often leaving burrs as well, all resulting in an inaccurate butt up against the rebate face on the motor shaft. My grinder came with stamped side clamps, with a hole that was 1.5mm larger than the shaft it slid over, while the part of the shaft the clamp would butt up against, was only 2.5mm greater in diameter than the wheel part of the shaft. That gave the side clamp freedom to wobble about, with no good face register.

Solved by making decent machined side clamps..

Joe

mick7026/08/2018 12:55:07
524 forum posts
38 photos

i have an old one that had no guards.

pigtail on one side and made adaptor for other that holds a flap disc from angle grinder

mechman4826/08/2018 18:32:17
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2461 forum posts
371 photos
Posted by mechman48 on 26/08/2018 11:24:52:
Posted by Neil Lickfold on 25/08/2018 22:08:38:

I have found that the hole size of the wheel and that of the shaft, is too loose. I suggest either turning a better inner bush, for the wheel, or using some form of tape, to make up the diameter to a better fit. Once the wheel is in position and clamped it will be good. Cheap wheels need the sides dressing as well as the diameter.

Back in the old days abrasive wheel manufacturers supplied spare bushes to compensate for different shaft diameters or the inner bushes were made from lead & could be made to suit shaft, not so these days. I strongly suggest that you DO NOT use tape around the motor shaft, you will only introduce imbalance & concentricity issues with the wheel, far better to make up new inner bushes to suit.

George.

P.s don't for get about ring test... if wheel looks ok doesn't mean to say it is... tap lightly with wooden implement, plastic handled driver or similar... it should give a clear 'ring' if it doesn't & just sounds dead / flat tone … bin it! there may be a hair line crack that you can't see so once it runs up to speed centrifugal will make it shatter

edited by George to inc. ring test.

 

 

 

Edited By mechman48 on 26/08/2018 18:33:25

Trevor Crossman 126/08/2018 19:59:07
125 forum posts
15 photos

I bought one of these cheapo Chinese grinders to use as a base upon which to build a Worden type tool grinder. I forget the brand, there are many of the same item from different suppliers in different colours. Anyway, out of the box, the vibration was awful, the washers were as Joseph Nocci mentioned- poorly stamped, so new ones made but it still vibrated. I ran it with no wheels and found the vibration to be caused by the incredibly poor quality ball races, the radial play could be readily felt at one end of the shaft so these bearings were removed and new FAG items fitted. It now runs beautifully smoothly, so some Norton wheels next.

I fully accept that it will not have the duty cycle of my industrial grinder, but it is only to be used as a tool grinder for quite lightweight, occasional work...….and still much cheaper than buying an old Clarkson or similar.

Trevor

derek hall 123/09/2018 06:32:06
46 forum posts

Just a couple of questions

I use HSS in my workshop for my lathe tools, I am looking for a replacement bench grinder and it seems an old good un beats a new bad un according to some people on here. So I am looking around various places, if I buy an old but good 7 or 8 inch grinder can I put a 6 inch wheel on it? I suppose as long as the speed doesn't exceed the max wheel speed it should be ok...

I notice that many pics posted on here show a cup wheel being used is this a better proposition than a normal straight wheel?

I am considering building Harold Halls grinding attachment this winter but cannot decide which, the basic or advanced any advice would be gratefully received. Any restriction on wheel type or size?

Any advice on diamond wheels for hss?

Oh dear that's more than 2 questions! Btw I did my grinding wheel course on my 21st birthday that was 39 years ago...expect its changed a bit since then.

As always your advice is appreciated

Regards

Derek

Georgineer23/09/2018 10:30:19
260 forum posts
14 photos

Posted by derek hall 1 on 23/09/2018 06:32:06:...

I did my grinding wheel course on my 21st birthday that was 39 years ago...expect its changed a bit since then.

Yes, they've taken the handles off and fitted electric motors instead.

George

derek hall 123/09/2018 10:48:03
46 forum posts

smiley....well it was last century and all in monochrome...

Ian S C23/09/2018 11:34:24
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7447 forum posts
230 photos

Someone mentioned dressing the side of the wheel,ok, BUT remember that there must be the compressable paper disc/washer on each side of the wheel. One store in NZ (Where every one gets a bargain) was, and may still be selling wheels with no paper washer, I did talk to the manager of one store, telling him of the danger of burst wheels, and the liability of the company in the event of the death of one of their customers, I don't think he understood.

Ian S C

Nicholas Farr23/09/2018 12:50:31
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1977 forum posts
937 photos
Posted by derek hall 1 on 23/09/2018 06:32:06:

Just a couple of questions

I use HSS in my workshop for my lathe tools, I am looking for a replacement bench grinder and it seems an old good un beats a new bad un according to some people on here. So I am looking around various places, if I buy an old but good 7 or 8 inch grinder can I put a 6 inch wheel on it? I suppose as long as the speed doesn't exceed the max wheel speed it should be ok...

 

Regards

Derek

 

Hi Derek, it is possible that a grinder with 7 or 8 inch wheels will run too fast for a 6 inch wheel, so check that out to start with. The other thing is that the rest that supports the work, may not reach the 6 inch wheel, especially after it has been dressed a few times. Always best to use the correct wheel for the grinder and the correct grinder for the wheel.

Regards Nick.

Edited By Nicholas Farr on 23/09/2018 12:51:21

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